Sound-box mounting



April 9, 1929. M NYSTROM 1,708,320.,

S OUND BOX MOUNTING Filed May 25, 1927 .5 0 j [if Fig-5 I :I l rvij,*-r*:

Inventor: F295 Hutin N strom.

Patented A 9 19 UNITED STATES 1.7%,326 PATENT OFFICE.

MARTIN NYSTR-OM, OF CHICAGO, ILLINOIS, ASSIGNOR TO BRUNSWICK-BALKE-COLLENDER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE,

' SOUND-BOX Application filed May 25 7 This invention relates to soundboxesfor talking machines and has a special relation to mountings bywhich the sound boxes are secured to tone arms.

An object of the invention is to provide an especially durable andsimple vibration insulating mounting for sound boxes.

Other objects and advantages will appear as the description proceeds.

Fig. 1 is a side elevational view, partly in section, of a sound box andtone arm connection embodying the invention;

Fig. 2 is a rear elevational view of the sound box;

Fig. 8 is a side elevational view of one end of the tone arm;

Fig. 4 is a front elevational view of the same; and

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4.

Referring to the drawings 1 indicates a sound box casing having adiaphragm 2. The back plate 4.- of the sound box casing is provided witha sleeve 7 formed integral therewith or otherwise attached thereto,which is spaced outwardly of an opening 8 in the back plate.

A tone arm 10 has secured thereon by means of pins or rivets 11. or inany other suitable manner, a collar 12 made of metallic material such asaluminum for example. While aluminum is preferable, it will beunderstood that other metals may be used. Lead, for example, has beenemployed, but due to its weight would not be so desirable as aluminum.The collar 12 constitutes substantially an enlargement of the end of thetone arm and is of such a size and thickness that it will fit snugly inthe sleeve 7 on the sound box. Two of the pins or rivets 11 may extendbeyond the outer face of the collar and are adapted to engage in bayonetslots 13 provided in the sleeve 7 for detachably securing the tone armto the sound box.

. In order to obtain a tight and snug connection between the tone arm orsound conveying tube 10 and the sound box casing, the collar 12 may beprovided with plurality of cushions 14 preferably of soft rubber.although cork or other resilient material may be used, adapted to bearagainst the back plate 4 when the parts are assembled. In theconstruction illustrated three such cushions spaced an equal distancefrom each other are provided, although a smaller or larg- MOUNTING.

1927. Serial No. 193,994.

or number may be used. The cushions 14 are disposed in openings 15provided in the collar and are held in place by friction or an adhesivesubstance such'as glue. The rear of the openings 15 communicate with theatmosphere by means of small ducts 16 which permit the escape of airwhen the cushions are forced into the openings and thus facilitate theassembly of the cushions. As the cushions bear against the back plate,they maintain the sleeve in engagement with the pins 11 and preventvibrations set up in the sound box from causing the sleeve to rattleagainst the pins.

The novel mounting prevents relative movement between the sound box andthe tone arm and also prevents vibrations in the sound box from beingtransmitted to the tone arm and in fact, acoustically insulates thesound box. Thus vibration of the tone arm is prevented and the qualityof reproduction of the talking machine is enhanced.

The aluminum collar 12 will remain in operative condition indefinitelyas it will not corrode nor will it be torn away or otherwise damagedwhen the operator removes or replaces the sound box.

While the collar is shown secured to the tone arm, it will be understoodthat it may be connected to the sleeve or, if preferred, it may beplaced on the inside of the tone arm, in which case the sleeve wouldalso be connected on the inside; the main object being to effectivelysound insulate the two members from each other.

While I have described a preferred form of my invention in detail, I donot wish to be limited to the exact form shown for many changes may bemade within the scope of the invention as defined in the appendedclaims.

Having thus described my invention, what I claim as new and desire tosecureby Letters Patent of the Jnited States is 1. The combination of asound box, a sleeve, a tone arm having a tubular end, arranged coaxiallywithin said sleeve a metallic collar interposed between the sleeve andthe tubular end and resilient cushioning members seated in said collarand extending therefrom, said metallic member serving as a rigid supportfor said resilient projections.

2. The combination of a sound box cas ing having a back plate with anopening therein, a sleeve formed integral with said back plate andspaced outwardly from the opening, tone arm having a collar securedthereto means for mounting said collar-on" saidsleeve andresilient'means carried by said collar and compressed between saidcollar and said back plate when'the parts are assembled. 5

3. The combination of a sound box casing provided with a back platehaving an opening and a sleeve on said back plate, a

tone arm having" a. collar secured thereto pressed between said collarand said back plate adjacent said opening; therein when the parts areassembled, and means for detachably securing said collar tosaid sleeve.

The combination. of a sound boxhaving anopening a tone arm having anenlarged end which is provided with a pluralityof openings,a pluralityof cushions fitting in said openings respectively, and projectingtherefrom and engaging said sound box adjacent said opening and means todetachably secure-said tone. arm 'tosaid T NYSTROM;

